Impulse starter for ignition generators



Mar. 27, 1923. 1,450,10.

' 0.11. TOWER.

IMPULSE STARTER FOR IGNITION GENERATORS.

' FILED AUG.4,1919.

ATM

' f jgigmunm Patented Mar. 27, 1923.

UNITED STATES ,45,0l PAENT OFFICE.

CHARLES H. TOWER, OF CLEVELAND, OHIO, ASSIGNOR TO THE TEAGLE COMPANY,

CLEVELAND, OHIO, A CORPORATION OF OHIO.

IMPULSE STARTER FOR IGNITION GENERATORS.

Application filed August 4, 1919. Serial No. 315,169.

To all whom it may concern:

Be it known that I, CHARLES H. TOWER, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented certain new and useful Improvements in Impulse Starters forIgnition Generators,"'of which the following is a specification,reference being had therein to the accompanying drawings. This inventionrelates to that class of driving mechanisms for the ignition generatorsof internal combustion engines which are designed to give the rotor ofthe generator a rapid movement intermittently when the driver is turnedslowly on the starting of the engine, such driving mechanisms beingcommonly known as impulse starters.

One object of the invention is the attainment in a mechanism of thecharacter in question of a high degree of uniformity and reliability ofoperation.

Another object of the invention is the production of an impulse startermechanism having working parts that are simple and rugged, of a minimumnumber and capable of production at low cost.

A further object of the invention is the provision of an impulse startermechanism that cannot go into operation when the generator is runningabove a predetermined speed.

Other objects of the invention more or less incidental or ancillary tothe foregoing will appear in the following description of the preferredembodiment of the invention.

In the accompanying drawings Fig. 1 is an end elevation of a portion ofan ignition current generator showing my improved impulse startermechanism with the locking parts in inoperative positions.

Fig. 2 is a similar view showing the locking parts of the impulsestarter mechanism in operative positions.

Fig. 3' is a section on the line 33, Fig. 1. Fig. 4 is an elevationof aportion of the impulse starter mechanism detached from the generator. Y

Fig. 5 is a fragmentary section on the line 55, Fig. 1.

Referring in detail to the construction illustrated,f1 designates one ofthe end plates of an ignition generator of the permanent magnet ormagneto type, 2 is the rotor shaft of the generator and 3 is one of theshaft bearings by which the shaft is supported at one end in the endplate 1. These are the usual generator parts. The impulse startermechanism comprises a driven member 4 which is keyed on the tapered endof the shaft 2. This driven member has its periphery formed with one ormore, and pref- I erably two, diametrically opposite notches to provideratchet shoulders 4 4. On the hub of the driven member or ratchet 4 isrotatably mounted a driving member 5, the shaft 2 and the driving anddriven members being secured in operative relation by a suitable nut 6and washer 7 on the end of the shaft. On its outer face the drivingmember 5 is provided with clutch teeth of lugs 5 adapt ed to be engagedin well known manner by another clutch driving member.

In the annular chamber formed between the ratchet or driven member 4 andthe drivingmember 5 are arranged a coiled driving spring 8 and similarbuffer spring 9, said springs being interposed between pins or posts 10and 11 carried by the driven and driving members, respectively. When thedriving member is turned in the direction of the arrow, Fig. 1, drivingforce is transmitted through post 11, spring 8 and post 10 to the drivenmember 4. In Figs. 1 and 2 the driving and buffer springs are shown intheir expanded or normal condition.

The driving member 5 is formed with opposite flanges 5 5 which bearagainst the outer face of the peripheral part of the driven member 4 andextend radially beyond said peripheral part. The front edge of eachflange is shaped to form a cam 5 for a purpose which will presently be6X- plained. In the normal relation of the parts shown in Fig. 1 thecams 5 lie angularly to the rear of the ratchet shoulders 4. The rearedge 5 of each flange normally lies slightly in advance of the adjacentratchet notch of the driven member.

Above the rotor shaft of the generator is a bracket casting 12 rigidlysecured to the generator end plate 1 by a screw 13 and a screw bolt 14.The casting 12 is provided with a pivot stud l2 directly above thegenerator shaft 2 and. on this pivot stud is mounted a locking pawl 15which is preferably forrned from square bar stock and secured on thestud by cotter pin 16. Thelonger end of this pawl is adapted to rideuponthe peripheries of the driven member 4 and the driving member 5 andto engage EEO - dog faces 17 a and 17 b moves from ing pressure exertedby and dash lines in this will presently several figures of latter israised of a coiled spring 18 which has its opposite end attached to apivot stud 19 mounted in a lug 12 of the casting 12. The outer end ofthe dog 17 is formed to provide a face 17 and a second face 17", and atthe junction of these faces is formed a knife edge 17 These and theknife edge 17 are adapted to co-operate with the adjacent end surface15, upper surface 15 and corner 15 of the pawl 15. When the'pawl 15engages the ratchet l, as indicated in Fig. 2,

the face 17 a of the dog is pressed against the,

corner of the pawl so as to hold the pawl yieldingly in engagement withthe ratchet. If the pawl be raised dog 17 is forced to the right by thecorner of the pawl until said corner passes the corner or knife edge 17of the dog whereupon the said knife edge or the face 17 b of the dogengages the upper surface 15 of the pawl and holds the latter yieldinglyin inoperative position out of engagement with the ratchet 4, asindicated in -Fig. 1. As the pawl 15 its operative position, shown inFig. 2, to its inoperative position, shown in Fig. 1, its knife edgecorner 15 comes into engagement with the knife edge 17 of the catch dog17, as indicated in Fig. 4. The parts are so formed and related thatwhen this occurs the yieldthe dog on the pawl is on a line passing toone side'of the axis of the pawl pivot, as indicated-by the dot Fig. 4.The purpose of be explained. stud 19 is mounted a manual which isnormally held by the position shown in the the drawing.- The' upper endof this lever 20 is adapted to be actuated by a pull wire 22 or the likewhile the lower cam end of the lever-is arranged to engage the longerend of the pawl 15 when the to inoperative position. By pulling on thelever 20 the long end of the pawl can be forced downward until its knifeedge 15 passes the knife edge 17 c of the dog 17 whereupon the latterpresses the pawl yieldingly against the ratchetA.

The casting 12 is drilled through from top to bottom to form an oilpassage which is closed at its outer end by a spring pressed ball 23 andis provided at its lower end with a tube 24 which projects into an oilreservoir 25 formed in 'On the'pivot cam lever 20 coiled spring 21 inthe latter with lubricant.

In the operation-of the mechanism, as

from the ratchet, the

the end plate 1 of the gen-' suming that the pawl 15 is in engagementwith ratchet 4, as shown in Fig.2, movement of the driving member 5 inthe direction. of the arrow will a compression of the driving spring 81nasmuch as the driven member isheld against turning by the pawl 15.When the driving member is turned in relation to the driven member untilthe cam 5 engages the end of the pawl 15, the continued movement of thedriving member causes said cam to force the pawl out of engagement withthe ratchet shoulder 4 thus releasing the driven memher and permittingit to by the driving spring 8 so as to give the rotor of the I generatora quick forward movement adapted to generate a strong high tens1oncurrent.

The endof the pawl 15, after disengagement from the ratchet shoulder,ridesupon the flange 5 until the diametrically opposite ratchet notchcomes under the pawl whereupon the latter engages the second ratchetshoulder and the operation is repeated. This continues to occur untilthe engine starts under its own power and acquiressome speed. As soon asthe speed of rotation reaches a certain predetermined-point the force fthe cams 5 on the locking pawl 1 is sufiicient to throw it upwardagainst the tension of the spring 18 into its inoperative position,shown in Fig. 1, and thereafter the rotor of the generator is driven. innormal fashion in unison with the driving member 5. When the :engine hasbeen stopped and it is agaim desired to start it the locking pawl 15 isthrown down into operative position by simply pulling on the lever 20.In a this connection, it will be observed that the manual lever 20 hasno engagement whatever with the pawl 15 when the latter is lowered andin operation and consequently does not interfere with the free operativemovements of said pawl.

As it would subject the mechanism to a ,severe shock if the locking pawl15 were permitted to engage the ratchet when the generatorwere runningat high speed. I have designed means to prevent this occurring. That isto say}. I so proportion the radius of the flanges 5*, 5 and the radiusof the ratchet Land so arrange the rear edges of notches of the ratchet4. as to prevent engagement of the pawl 15 with the ratchet shoulderswhen the speed of rotation is above a certain value. It will be observedthat the peripheries of the flanges'5 5 project radially considerablybeyond the periphery of. the ratchet 4, and the rear edges 5, 5 of theflanges 5 5". while sufficiently in advance of the ratchet notches topermit the pawl 15- to ride into said notches when the speed of rotationis low, are yet sulficiently near said notches so that the inertia besnapped forward 7 the flanges 5?, 5 in relation to the of the pawl 15,as it rides on the peripheries of flanges 5", 5", will prevent itsriding into the notches when-the speed of rotation is increased beyond acertain moderate value below which sudden engagement of the-pawl andratchet would not be harmful.

By reason of-the relative form and arrangement of the pawl 15 and dog 17it is impossible for these parts to interlock with the pawl in a neutralor, intermediate 'posl tion' as has tended to occur in priorconstructions, since when the knife edges 15 and 17 come into engagementthe pressure of the dog on the pawl acts automatically to move the pawlon its pivot and thus prevents the parts stopping on dead center..I-thus secure a uniform and reliable operation. Since the mechanismcannot accidentally go into operation when the parts are turningat highspeed the avoidance of undue shocks and strains is insured. Obviouslythe working parts are, simple, strong and easily de. What I claim is:

1. In an impulse starter mechanism for rotary ignition generators, thecombination of a rotatable driven member having a ratchet shoulder, astop pawl adapted to engage saidshoulder and hold the driven member fromturning, .a rotatable driving member adjacent to and coaxial with the Idriven member, a driving spring between the driving and driven members,the driving member having means for; disengaging the pawl from the stopshoulder when the spring is compressed, a movably: mountedspringpressedcatch adapted 'to engage and yield ingly hold the pawl inoperative engagement with the driven member and to engage andyiieldingly hold the pawl out of engagement with the driven member whensaid pawl has been moved to inoperative position, and

. manual means for positively forcing the pawl from its inoperative toits operative position, said manual means having no en gagement with thespring-pressed catch or pawl when the latter is in operative positions.

2. In an impulse starter mechanism for ignition generators, thecombination with the generator shaft of means for driving said shaftcomprising a ratchet fast thereon, a cam mounted to turn in relation tosaid generator shaft, a spring interposed between the cam and ratchet totransmit power to drive the generator shaft, a pawl pivotally moved frominoperative the connection with the last mounted to engage and stop theratchet and I be disengaged therefrom by the cam, and a pivotedspring-pressed catch adapted byen; gaging one surface of the pawl tohold the latter yieldingly out .of contact with the ratchet and alsobyengaging. another surface of the pawl to hold the latter yieldingly incontact with the ratchet.

3. In an'impulse starter mechanism for ignition generators, thecombination with the generator shaft of means for driving saidshaftcomprising a ratchet fast thereon, I

a cam mounted to turn in relation to said generator shaft, a springinterposed between I i the cam and ratchet to transmit power to drivethe generator shaft, a pawl'pivotedanother surface of the pawl and holdthe.

latter yieldingly in contact with the ratchet. 4. In an impulse startermechanism for ignition generators, the combination with the generatorshaft of means for driving said shaftcomprising a ratchet fast thereon,a cam mounted to'turn in relation to said generator shaft, a springinterposed between the cam and ratchet to transmit power to drive thegenerator shaft, a pawl pivotally mounted' to engage and stop theratchetand be disengaged therefrom by the cam, means comprising a pivoted catchandaspring adapted to yieldingly hold the pawl in operative engagementwith the driven. memher and to hold the pawl out of engagement with thedriven member when said pawl has been moved to inoperative position, andmanual means for causing the pawlto be 7 to operative position, saidmanual means'ha'ving no opera- I named spring other than through thepawl.

In testimony whereof, I hereunto aflix my signature.

v CHARLES H. rowan.

